Chronic plaque psoriasis, the chie...

Chronic plaque psoriasis, the chiefly common form of psoriasis, is a papulosquamous disease defined by dint of erythematous plaques with a silvery scale. The diagnosis usually is clinical, on the contrary occasionally a biopsy is necessary. Psoriasis affects 06 to 48 percent of the U population, and about 30 percent of affected patients have a first-degree relative with the disease. Psoriasis is a T-cell-mediated autoimmune disease, nevertheless certain medications and infections are well-known risk factors. Management of psoriasis includes education about chronicity, realistic expectations, and use of medication. Steroids and vitamin D derivatives (eg calcipotriene) are the mainstays of topical therapy. Topical steroids and calcipotriene together may work better than either agent alone. Patients with psoriasis involving more than 20 percent of their skin or those not responding to topical therapy are candidates for light therapy; traditional systemic therapy; or systemic treatment with immunomodulatory put drugs intos such as alefacept, efalizumab, and etanercept. (Am Fam Physician 2006;73:636-44 646 Copyright [c] 2006 American Academy of Family Physicians.)

The prevalence of psoriasis in the United States is estimated to be 06 to 48 percent (1) Psoriasis is slightly more belonging to all in men. (1) No reliable data exist to support the for the use of all assumption that psoriasis is les often met with in blacks. (1) There is a bimodal attack (i.e., late teens and late 50s) and early-onset disease is more often met with (2)

About 30 percent of patients with psoriasis have a first-degree relative with the disease, and those with early-onset disease are more likely to have a family history of psoriasis. (12) These facts impart support for a genetic basis for the disease, and several chromosome loci have been implicated. (3) The disease is not exclusively genetic, however, because several environmental factors also appear to play a role

Pathogenesis

Psoriasis is a T-cell-mediated autoimmune disorder. (4) The proces begins with an environmental factor, perhaps a viral antigen, which induces T small cavitys to produce cytokines. The cytokines stimulate keratinocyte proliferation and production of antigenic adhesion ultimate particle s in the dermal blood tubes These adhesion molecules further stimulate T confined apartments to produce cytokines, thus perpetuating the replication (5) Immunomodulatory drugs, which target the mechanism just described, proffer novel treatment options for psoriasis. (5) These medicines also known as biologics, are discussed later.

Risk Factors

Psoriasis is associated with several risk factors that may provide the environmental stimulus to T-cell proliferation. They include psychological stres certain medications (lithium, beta blocker antimalarial unsalable articles nonsteroidal anti-inflammatory drugs, and oral steroid withdrawal), (6) and infection. Although a link between psoriasis and stres be seens to exist, evidence to support a causal relationship is lacking. (7) Chronic human immunodeficiency virus infection is associated with accurate psoriasis exacerbations. (8)

Diagnosis

The diagnosis of psoriasis is based forward the clinical appearance of skin lesions. Biopsy may be necessary, however, to distinguish psoriasis from other conditions with similar appearances in the same state [i]or[/i] condition as lichen simplex chronicus, nummular eczema, seborrheic dermatitis, and tinea corporis.

PLAQUES

Chronic plaque psoriasis typically is symmetric and bilateral (Figure 1) Lesions begin as papules and eventually coalesce to form plaques. Plaques are well demarcated and concealed by a silvery scale (Figure 2) Plaques exhibit the Auspitz sign (bleeding after the removal of scale) and the Koebner phenomenon (lesions induced from trauma). Most patients (84 percent) with psoriasis report itching; the word psoriasis is derived from the hellene word for itching, "psora." (9)

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DISTRIBUTION

The extensor surfaces (elbow and knees) commonly are involved (Figure 3) as well as the lower back, scalp (Figure 4) and nails. Nail changes include onycholysis (separation of the nail from its bed; Figure 5) pitting (Figure 6) oil blemishs (yellow or brown spots caused by the agency of cellular debris under the nail), and nail dystrophy mostly patients eventually develop nail involvement, although nail findings lead skin findings in about 4 percent of patients. (1011) Older patients and those with longer duration of disease, extensive skin lesions, or joint involvement have more nail involvement. (1012)

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Inverse psoriasis, or flexural psoriasis (Figure 7) affects intertriginous areas similar as the gluteal fold, axillae, and glans of the uncircumcised penis. Scale may not appear in these areas.

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COMPLICATIONS

Chronic plaque psoriasis does not affect longevity. The condition may, however, be complicated by dint of several comorbidities including malignancy, arthritis, and emotional distress from the cosmetic tenors of the disease. Depression, anxiety, sexual dysfunction, poor self-conceit and suicidal thoughts may coexist with psoriasis, on a level in patients with less exact disease. (13)